The present disclosure relates to flexible grips for the shaft of a golf club and particularly such grips made from elastomeric material. Typically, such grips are formed of elastomeric material sized so as to be slightly stretched when received over the club shaft to provide sufficient friction to resist the forces applied to the club during the downswing.
FIG. 1 is a perspective view of a flexible elastomeric grip for a golf club shaft currently in widespread use showing a body portion 1 with an end cap 2 which is usually formed of elastomeric material having a higher durometer than the body portion.
FIG. 2 shows a cross section of an elastomeric flexible grip for a golf club shaft of the type currently in widespread use as having an integrally formed substantially closed end 3 molded simultaneously with the body portion 4 to form a one-piece grip.
It has been desired to employ electronic sensors or counterweight in the butt end of the grip in order to measure the swing characteristics such as, for example, the speed of the downswing and the arc or plane of movement. It is proposed to locate such a sensing device in a cavity formed in a cap provided on the end of the grip because the cap has the largest diameter of the grip. If the length of the grip is extended beyond the end of the club shaft in order to provide additional space to accommodate the sensor or counterweight, the grip becomes less resistant to bending and this can result in increased lateral deflection or oscillation of the grip which results in “wobble” that can create an unstable feel for the user resulting in degradation of the quality of the downswing. The phenomenon can be particularly troublesome where a balance counterweight is included in the cap, particularly if counterweight is employed in conjunction with a sensing device resulting in a significant increase in the length beyond the club shaft due to the requirement for a larger cavity in the cap.
Efforts to reduce the cap wobble and resistance to lateral deflection, particularly where the sensing device and/or counterweight are employed in the cap, have been directed to forming the cap from a harder elastomer or elastomer having a higher durometer than the remaining portions of the flexible grip. However, if the harder material is present on the exterior surface of the golf grip, this results in a harsher feel and less slip resistance than experienced with elastomer of lesser durometer and will lessen the feel of the grip to the user. Thus, it has been desired to find a way to accommodate sensing devices and/or counterweights in the cap of an elastomeric golf club grip in a manner which does not degrade the feel of the grip and yet provides resistance to lateral deflection or wobble.